As energy shortages become more severe, increased efficiency utilization of heating systems using available lower priced fuel is desirable. In response, add-on convective and forced air heaters have become available for installation in wood burning stoves. These prior art heaters generally are placed in the fireboxes of the stoves in close proximity with the fire, often also serving as a grate. In this placement they are exposed to the high temperature of the flame and the corrosive environment of the ash. As a result they are subject to burn out and are short lived. In addition many stoves, such as the Franklin stove, have small fire boxes so that these prior art add-on forced air heaters leave little room for the fire and are aesthetically objectionable.
Forced air heaters of the type shown in the present invention are well known in the prior art as integral parts of stoves or furnaces. However, they are not adaptable for installation in existing stoves not so equipped. In fact these integral units could not readily be adapted for this use.